A congestion assistant is a driver assistance system based on an information fusion of an adaptive cruise control and a lane centering assist. The congestion assistant is configured to accelerate, brake and steer a motor vehicle autonomously, i.e. in an automated manner.
An adaptive cruise control (“ACC”) or adaptive speed control or automatic distance control (“ADC”) is understood to mean a speed control system in motor vehicles that, in controlling the speed, incorporates a distance to a motor vehicle driving in front as an additional feedback and correcting variable.
The adaptive cruise control may form part of a radar-supported emergency braking assistant. Adaptive cruise controls of this type enable an automated full braking to the point of stopping (e.g. in stop-and-go traffic). With a stop-and-go function, autonomous starting after briefly stopping or driver-triggered restarting is possible, e.g. following driver confirmation by tapping on the accelerator pedal or actuating the control lever, up to the speed predefined by the driver. This function serves to provide extra comfort for the driver in urban traffic and in tailbacks on motorways.
The lane centering assist (“LCA”) is configured to stop the motor vehicle automatically in a center of a lane on a road. The lane centering assist can use e.g. data of a radar system and/or a camera, such as a stereo camera. An orientation takes place based on e.g. lateral boundary lines of the lane and, where relevant, additionally based on a vehicle driving in front. A lane departure warning system can furthermore be configured to avoid an unintentional departure from the lane and collisions with objects to a side of the vehicle through active steering interventions.
The camera of the lane departure warning system is used during operation for the orientation. The congestion assistant thus obtains information on a road layout using road markings and a direction of the vehicle ahead. The congestion assistant can also decide whether the road or the vehicle ahead should be followed. The motor vehicle is thereby prevented from following a motor vehicle that is turning off or changing lanes. A distance to the vehicle ahead is continuously controlled by the adaptive cruise control.
The congestion assistant becomes active automatically when the driver has switched the congestion assistant to standby and general external conditions allow its activation.
However, unwanted deactivations of the congestion assistant may occur if, for example, due to unfavorable weather conditions, a side line and/or center line detection is not possible, a quality of the road markings is poor, or the motor vehicle is located in an area of roadworks. This may confuse and irritate the driver.